Application of 70 kVp tube voltage combined with the FLASH in low-dose CT of pediatric paranasal sinus / 中国辐射卫生

Objective To evaluate the feasibility of dual-source low-dose computed tomography (CT) of the paranasal sinus in children, with acquisition at an ultra-low tube voltage (70 kVp) combined with the Flash scan. Methods CT scans of the paranasal sinus were performed on 80 pediatric patients who were divided into two groups according to different protocols (70 kVp protocol with Flash scan mode and the iterative reconstruction, pitch 3, the experimental group (group A), n = 40; 80 kVp protocol with conventional spiral mode, pitch 1.5, control group (group B), n = 40). For each examination, the CT dose index (CTDIvol), dose-length product (DLP) and effective dose (ED) were estimated. The image noise, signal-to-noise ratio (SNR) and overall subjective diagnostic image quality were also evaluated. Results The images of these two groups were all satisfied for the clinical diagnosis. For radiation dose, the CTDIvol (mGy), DLP (mGycm) and ED (mSv) values of the 70 kVp protocol were significantly lower than those of the 80 kVp protocol [CTDIvol: 0.39 ± 0.004 vs1.57 ± 0.009 mGy, P < 0.001; DLP: 6.31 ± 0.52 vs 19.88 ± 2.01 mGycm, P < 0.001; ED: 0.024 ± 0.005 vs 0.079 ± 0.016 mSv, P < 0.001. Compared with those of the 80-kVp protocol, the image noise and the SNRbone increased, the SNRsoft-tissue decreased. There was no statistical difference in the subjective scores of the two groups of image quality by the two physicians (P > 0.05). Conclusion When diagnosing the paranasal sinus in children, an ultralow tube voltage (70 kVp) combined with the Flash scan technique can reduce the radiation dose significantly while maintaining diagnostic image quality with clinically acceptable image noise.

The application value of high pitch scanning technique of dual source CT combined with Iomeprol 400 in aortic angiography / 实用放射学杂志

Objective To investigate the effect of a combination of second generation high pitch scanning technique of dual source CT and Iomeprol 400 on image quality,total iodine dose and injection speed.Methods Eighty-four patients with clinically suspected aortic disease underwent aorta CT angiography (CTA)were randomly divided into two groups (42 cases in each group).The experimental group used high pitch dual source CTA acquisition mode (pitch 3.2)combined with Iomeprol 400 contrast agent.The control group used conventional CTA scan mode combined with Iopamidol 370 contrast agent.The differences in image quality,effective radiation dose, total iodine dose and injection speed between two groups were compared.Results There were no statistical differences in CT value, signal-to-noise ratio,contrast-to-noise ratio and subjective image quality score between two groups (P>0.05).There were significant statistical differences in CTDIvol,DLP and CT value of the superior vena cava between two groups (P<0.01).The total iodine dose and injection speed were reduced in experimental group.Conclusion The combination of a high pitch scanning technique of aorta CTA with Iomeprol 400 contrast agent can reduce radiation dose and potential hazards of contrast agents on the premise of guaranteeing the image quality.

Image Quality and Radiation Dose of High-Pitch Dual-Source Spiral Cardiothoracic Computed Tomography in Young Children with Congenital Heart Disease: Comparison of Non-Electrocardiography Synchronization and Prospective Electrocardiography Triggering

OBJECTIVE: To compare image quality and radiation dose of high-pitch dual-source spiral cardiothoracic computed tomography (CT) between non-electrocardiography (ECG)-synchronized and prospectively ECG-triggered data acquisitions in young children with congenital heart disease. MATERIALS AND METHODS: Eighty-six children (≤ 3 years) with congenital heart disease who underwent high-pitch dual-source spiral cardiothoracic CT were included in this retrospective study. They were divided into two groups (n = 43 for each; group 1 with non-ECG-synchronization and group 2 with prospective ECG triggering). Patient-related parameters, radiation dose, and image quality were compared between the two groups. RESULTS: There were no significant differences in patient-related parameters including age, cross-sectional area, body density, and water-equivalent area between the two groups (p > 0.05). Regarding radiation dose parameters, only volume CT dose index values were significantly different between group 1 (1.13 ± 0.09 mGy) and group 2 (1.07 ± 0.12 mGy, p 0.05). CONCLUSION: In high-pitch dual-source spiral pediatric cardiothoracic CT, additional ECG triggering does not substantially reduce motion artifacts in young children with congenital heart disease.

Does stapes surgery improve tinnitus in patients with otosclerosis? / A estapedotomia melhora o zumbido em pacientes com otosclerose?

Abstract Introduction: Otosclerosis (OS) is the primary disease of the human temporal bone characterized by conductive hearing loss and tinnitus. The exact pathogenesis of tinnitus in otosclerosis patients is not known and factors affecting the tinnitus outcome in otosclerosis patients are still controversial. Objectives: To find the effect of stapedotomy on tinnitus for otosclerosis patients. Methods: Fifty-six otosclerosis patients with preoperative tinnitus were enrolled to the study. Pure tone average Air-Bone Gap values, preoperative tinnitus pitch, Air-Bone Gap closure at tinnitus frequencies were evaluated for their effect on the postoperative outcome. Results: Low pitch tinnitus had more favorable outcome compared to high pitch tinnitus (p = 0.002). Postoperative average pure tone thresholds Air-Bone Gap values were not related to the postoperative tinnitus (p = 0.213). There was no statistically significant difference between postoperative Air-Bone Gap closure at tinnitus frequency and improvement of high pitch tinnitus (p = 0.427). There was a statistically significant difference between Air-Bone Gap improvement in tinnitus frequency and low pitch tinnitus recovery (p = 0.026). Conclusion: Low pitch tinnitus is more likely to be resolved after stapedotomy for patients with otosclerosis. High pitch tinnitus may not resolve even after closure of the Air-Bone Gap at tinnitus frequencies.

Resumo Introdução: Otosclerose (OS) é a principal doença do osso temporal humano caracterizada por perda auditiva condutiva e zumbido. A patogenia exata do zumbido em pacientes com otosclerose não é conhecida e fatores que afetam o desfecho de zumbido em pacientes com otosclerose ainda são controversos. Objetivos: Encontrar o efeito da estapedotomia sobre o zumbido em pacientes com otosclerose. Método: Foram incluídos no estudo 56 pacientes com otosclerose com zumbido pré-operatório. Os valores médios tonais do gap aero-ósseo, o tom de zumbido no pré-operatório, o fechamento do gap nas frequências dos zumbidos foram avaliados quanto ao seu efeito sobre o desfecho pós-operatório. Resultados: O zumbido em tom grave teve desfecho mais favorável em comparação com o zumbido agudo (p = 0,002). Os valores médios dos gaps pós-operatórios não foram relacionados com o zumbido pós-operatório (p = 0,213). Não houve diferença estatisticamente significativa entre o fechamento pós-operatório do gap na frequência do zumbido e melhoria do zumbido de tom agudo (p = 0,427). Houve diferença estatisticamente significativa entre a melhoria no gap nas frequências do zumbido e recuperação do zumbido de tom mais grave (p = 0,026). Conclusão: O zumbido de tom mais grave parece ser mais bem resolvido depois de estapedotomia em pacientes com otosclerose. O zumbido de tom agudo pode não desaparecer, mesmo após o fechamento do gap nas frequências do zumbido.

Application of high pitch dual source CT in the diagnosis of acute aortic dissection / 实用放射学杂志

Objective To investigate the application value of low dose high pitch dual source CT angiography technique in diagno-sis of acute aortic dissection.Methods 21 cases of critically ill patients with suspected aortic dissection underwent total aortic angiog-raphy without using ECG by adopting the second generation dual source CT Flash Technology (pitch 3 .2 ,1 0 0 kV and 1 0 0 mAs), using a lower contrast dose (60 mL).Results All subjects accepted as low as possible radiation doses and iodine intake;at the same time,accurate information including aortic intimal tear position,intimal flap,true and false lumen,and lesions involving the range vessel signs and anatomic relationship were received,2 cases of Stanford type A,type B 1 9 cases (2 cases of aortic rupture).Average scan time 2.6 s,average effective radiation dose cm 270 mGy·cm.Conclusion High quality images by using high pitch dual source CT low dose angiography with lower contrast dose provide safe,reliable,real-time screening method for critically ill patients with aor-tic dissection caused by systemic severe compound injury.

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

OBJECTIVE: To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. MATERIALS AND METHODS: Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 +/- 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. RESULTS: There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 +/- 0.306 [group A] vs. 1.084 +/- 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 +/- 0.16 mSv in group A and 7.1 +/- 1.05 mSv in group B (p = 0.001). CONCLUSION: In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.